The key to good offensive football is having a balanced attack with equal amounts of running and passing. With the emphasis on the passing game and the evolution of 8-man fronts and zone blitzing defenses, it has become more and more difficult to be able to effectively run the football. Over the past few weeks, we have had a lot of questions regarding zone blocking and exactly what that means. In this week's class we will try to explain zone blocking by the offense and why it has become a common scheme used to run the football.

What is zone blocking?

Zone blocking in the running game is when two or three offensive linemen work in tandem as opposed to each offensive lineman having a specific, predetermined man to block. Zone blocking involves the center, guard, tackle and tight end working in combination to block an area with an emphasis on double-teaming the defensive linemen who are aligned on the line of scrimmage.

The concept is for two adjacent linemen to come off in unison and attack a defensive line to the play side or to the side the ball carrier is going. The advantage, as opposed to man blocking, is that you create a double-team with two players blocking one defensive lineman. This allows the offensive linemen to be aggressive because he knows he has help if his defensive lineman was to pinch inside. It also provides movement at the point of attack, which can open creases for the running back.

Zone blocking initially starts out as a double team at the point of attack on the down defensive linemen, but the beauty of it is that one of the offensive linemen will leave to attack the linebacker while one stays to take over the defensive lineman. The key is for the two offensive linemen working in unison to double-team the defensive lineman to decide who and when one of them will leave to block the linebacker. In the diagram below, we show the offensive line starting the initial double team on the defensive lineman.

It appears that they have doubled the defensive end and defensive tackle and allowed the linebackers to go free, but both offensive linemen on the double team have all four of their eyes on the linebacker while the double team is taking place. One of the linemen will come off the double and block the linebacker.

There are several keys to this technique:
1. The linemen stay hip to hip.
2. The linemen keep their shoulders square.
3. Most importantly, all four of their eyes are on the linebacker.
4. Knowing when and who takes over the defensive lineman and who leaves to block the linebacker.

In the next diagrams, we show the technique of going from the double team to taking over the linebacker. If the end pinches inside, the guard will take over and the tackle will leave for the linebacker. (See below)

If the end stays outside, the tackle will take over and the guard will leave for the linebacker. (See below)

Difference between man blocking and zone blocking

Zone blocking first started to take place back when teams ran an old slant and angle defense. They would line head-up on an offensive lineman then slant the defense one way or another. It is easy to show this problem in man blocking and the best way to illustrate it is to show the defensive end pinching inside. If you are in man blocking and the tackle is assigned to the defensive end, he not only misses the defensive end pinching, but the DE knocks off the guard and keeps him from going to the linebacker.

There are different kinds of zone plays and you will often here the term the outside zone. In the figure below, we show the landmark of the back in the outside zone. It is obvious that at the angle the back takes the ball there is very little opportunity for the back to cut back behind the center. This affects all of the linemen's techniques because it is predetermined where the ball is going.

The inside zone is another term you hear. On the inside zone, the back's angle is more to the inside leg of the offensive tackle. Because the back is headed in a more straight-ahead angle, there is now the ability for the back to cut back behind the center. It is important that the back gets into the heels of the offensive linemen before he makes the cut. The offensive line can't allow penetration.

Pass blockingZone or Man
Zone-locking or man-locking principles may also be applied to pass blocking. Offensive linemen, when facing twisting defensive linemen, can also either lock on man-to-man or pass it off in a zone concept. When passing it off, or zone blocking, the key is to stop the penetration of the defensive end. In the figure below, the offensive tackle must stop the penetrating defensive end before passing him off to the guard. The offensive tackle then takes the defensive tackle looping around.

Conclusion
Zone blocking was created to handle moving defensive linemen. It is a simple concept, but it takes a lot of practice because it involves offensive linemen working in unison and decisions have to be made while the play is taking place. In zone blocking, you don't have a lot of different assignments, but you have a lot of techniques. It takes many repetitions to get the feel of working together as a unit. The diversity of zone blocking comes by the back running different angles and by the offense using different formations to confuse the defense.

Q & A with Bob Davie
First of all, thanks for all of the terrific responses and knowledgeable questions this week. Please keep sending in the questions and we'll tackle as many issues as we can this season. Here are a few of your questions regarding Cover 2:

Coach,

Which college teams this year are devising the best attack schemes to defeat the Cover 2 zone coverage and could you give some examples from some of the "September" games? Thanks!Brian Burnett
Colorado Springs, Colo.

Bob Davie: I don't have a specific example from this year, but I think there are a couple of concepts. The first depends on having a great tight end, like Miami last year. In this case, you try to get the tight end up the seam on the linebacker. Most teams attack Cover 2 the same way. Something I didn't mention is that when a defense deploys four defenders in Cover 2, that leaves a 7-man front. Teams will try to run the ball against it. There is not a specific team that comes to mind, but Miami with Jeremy Shockey comes to mind.

Coach,

Can a team that uses a base 3-4 defense use Cover 2? If so, how does it differ?
Reed David
Pittsburgh, Pa.

Bob Davie: Definitely. They have a few options too. First, defenses can use one of the outside or inside linebackers as the fourth rusher. You would still play a 5-under, 2-deep concept with a 4-man rush, but one of your linebackers becomes the fourth rusher. Another way a defense uses Cover 2 from a 3-4 base is to just rush three defenders and drop all four linebackers, with the two corners and play 6-under, 2-deep and have an extra underneath dropper as a "rat," who looks for crossing routes or quarterback scramble.

Thanks for explaining Cover 2, Coach Davie. I have one follow-up question: what happens with slot receivers? Seems like that's an immediate way to beat a zone, to put 2 or even 3 receivers on one side of the field. Does the D then have to audible to man-to-man? Many thanks--I'm learning a lot!

Derek Oja
Iowa City, Iowa

Bob Davie: No, you can play Cover 2 against any formation. The difficult thing with the slot is many times you get a linebacker that has to "walk out" particularly in a one-back set on the slot. That's how the evolution of nickel defenses took place. Teams will substitute a fifth DB for a linebacker to be able to play either zone or man-to-man coverage on the slot.

I appreciated you explanations of and insights into Cover 2. You mentioned that it is often important for a LB to read the WR's pattern, specifically if the WR had an outside release. You wrote that an outside release indicates that WR might be going deep and that the LB should play any inside receivers (RB, TE), man-to-man in case the offense is trying to stretch the safeties w/ 4 deep receivers. If a LB must read run first, how can he also read the WR releasing outside? It seems like too much to read and react to at the same time. GO DAWGS!Graydon Simkins
Tacoma, Wash.

Bob Davie: Great question! The outside linebacker always, always plays run first. The tight end will tell him if it's run or pass. If the TE blocks, the LB is obviously playing run. The only time he reads outside to the WR is if the TE releases pass. The LB should not kick into a pass read until the TE declares that it is a pass.

Editor's note: As architect of top defenses at Texas A&M and Notre Dame, Bob Davie is recognized as a top X's and O's coach. This season, Coach Davie analyzes offensive and defensive schemes as part of his season-long course on football for ESPN.com. Each week, he breaks out the chalkboard and break down the X's and O's in college football.